Ski and its method of manufacture



a'tented July T7, 1.951

Application July 11, 194i, serial No. 760,412 In France March 18, 1942Sectionml, Public Law 690, August 8, 1946 Patent expires March 18, 19626 Claims.

According to the methods in use to this day, the desired bend is givento skis during manufacture by softening the wood by means of steam orhot water after which the softened and vbent skis are dried on a heatedtable or like support. But after some time, the bend disappears unlessthe skis, when not in use, are held inside suitable pressing devices.

The softening of the wood by means of Warm water or by steaming producesalways an alteration in the wood fibres the resistance of which isthereby substantially reduced.

On the other hand, the fibres in contact with the heated support shrink'before the inner 1ibres and still longer before the fibres on theopposite side of the Wood. This progressive shrinking of the successiveinner layers of the wood produces inner stresses which cause cracks;

said cracks may not be noticed when the wood tain two skis having thesame suppleness, i. e.

the same resistance to bending and the same weight, which makes itnecessary to reduce the cross-section of either of the skis to obtain;with as great an approximation as possible, equality for these importantfactors from one ski to the other of the same pair of skis.

It is furthermore impossible to find two laths for the sliding portionsof the skis, which have exactly the same fibrous structure andVconsequently, the sliding or frictional factor is different for the twoskis of a pair, which is a considerable drawback for competition skis.

My invention has for its object a ski constituted by two superposedassembled boards one of which appears with its grain lying at and theother with grain upright.

My invention has also for its object a method for manufacturing sameaccording to which the two superposed boards are secured togetherthrough cold gluing and then bent by an energetic pressing against asuitable bending block during the drying thereof.

My invention has also for its object to provide the two skis of a pairwith identical sliding surfaces and equal suppleness'and to this end Iobtain the lower boards or elements of the skis (Cl. Zim-11.13)

by ripping a wood lathe of suitable size and outline and by using eachripped part with the surface formed by the ripping as the slidingsurface of the ski while the upperboards or elements of the ski aresimilarly obtained by ripping another wood lath.

I have shown by way of example in accompanying diagrammatical drawings aform of execution of my invention.

Fig. 1 shows the lath having flat or upright grain, as used for makingthe lower boards of a pair of skis.

Fig. 2 is a view of part of each lower board cut out of the lath of Fig.1.

Figs. 3 and 4 show the lath having upright or ilat grain (according asto whether the lath of Fig. 1 has flat or upright grain) used for makingthe upper boards of the same pair of skis.

Fig. 5 shows the two upper boards as obtained after ripping the lath ofFigs. 3 and 4.

Fig. 6 shows the upper and lower boards of a ski before they areassembled.

According to my invention, a lath 2 (Fig. 1) having flat or uprightgrain is cut to the size required for forming in superposition the twolower boards of a pair of skis.

Another lath 3 (Fig. 3) having grain in upright or flat arrangement;according as to -whether the lath 2 has at or upright grain, is cut tothe size and shape required for forming in superposition the two upperboards of the pairs of skis and assumes then the appearance shown inFig. 4.

The lath 2 is then ripped as shown by the line 4 (Fig. 1) so as to formtwo thin boards 5 and 6 (Fig. 2) which constitute the lower boards ofthe two skis. Care should be taken to use for the lower or slidingsurface of the finished skis the surfaces 1 and 8 (Fig. 2) which havebeen separated by the ripping operation and show consequently perfectlyidentical friction and sliding coefficients. These boards 5 and 6 whichhave a maximum suppleness or a maximum rigidity according as to whetherthey are cut with ilat or upright grain, may be of hard wood such as Yash, hickory and the like or else compressed or they are cut withupright or flat grain, these two boards will also provide maximumrigidity or maximum suppleness. The lower board 5 (or 6) and the upperboard l0 (or Il) are then glued together through their cooperatingsurfaces I2-I3 or Ill-l5 and held tightly against each other on asuitable bending block in which position they are retained until theyare completely dry.

This operation being performed, the ski is practicallydeformation-proof. This is due to the fact that the fibrous structuresglued together are not identical and consequently the stresses arisingin the two assembled boards are not identical and they oppose oneanother as one board cannot be deformed vwithout being submitted to thecounteracting resistance of the other board.

Moreover the surfaces which have been glued together are provided withstriations Aproduced by the saw used for ripping, which striationsengage one another from one board to'the other and assist in resistingdeformation.

Lastly in order to give the ski the shape of a solid of equalresistance, its cross-section should be rectangular Yand its breadthincreases from the centre towards the ends while .its thicknessdecreases. This outline allows the omission of the usual ribs providedfor giving rigidity which ribs at the same time prevent the obtaining ofthe desired suppleness which should be equally distributed over the skibearing surface in order to absorb any diiferences in ground level.

The skis made in accordance with the above method of manufacture showthus important advantages which no prior method has yet allowed, to wit:

1. Their flexibility and resistance are considerable for a minimumweight.

2. No harmful treatment alters the texture of the wood and itscomponents.

3. The two skis of a pair show the same flexibility, the same resistanceto permanent deformation and they have sliding surfaces which have thesame sliding factor from one ski to the other.

These advantages are still further increased by the possibility of usingcompressed or bakelised wood which produces an undeformable support thewear of which is practically nil and the Yhardness and toughness ofwhich is greater than if it were made of natural wood.

What I claim is:

1. A method for producing a pair of skis consisting in shaping a lath tothe outline of a ski, ripping it along a surface parallel to its outersurfaces, ripping a further shaped lath, gluing each ripped element ofthe first lath to a ripped element of the second lath to form a ski thelower surface of which is constituted by the ripped surface of the rstlath to obtain operative sliding surfaces that are exactly symmetricalfor both skis with reference to a longitudinal vertical plane separatingthem when lying in sideby-side relationship, the transversalcross-section of the contacting surfaces between the superposed rippedelements forming each ski extending rectilinearly across the ski,bending each ski formed by the superposed lath elements into final skishape and holding them in their bent shape during the drying of the gluebetween the ripped elements.

2. A pair of skis comprising two skis including each respectively one ofthe two boards obtained 4 through the ripping of a shaped lath to formthe lower members of the skis, each board having its ripped surfacedirected downwardly, and an upper board having a shape similar to thatof the corresponding lower board and contacting with said correspondinglower board along a surface the transverse cross section of which isconstituted by a straight line extending throughout the breadth of theskis, the outer lower surface of the lower boards of the two skisassuming thus structures that are exactly symmetrical with reference toa longitudinal vertical plane separating the tWo skis when lying next toeach other.

3. A pair of skis comprising two skis including each respectively one ofthe two boards obtained through the ripping of a shaped lath to form thelower members of the skis, each board having its ripped surface directeddownwardly, and one of .the two boards obtained through the ripping of afurther shaped lath, last mentioned lath forming an upper board having ashape similar to that of the corresponding lower board and contactingwith said corresponding lower board along a surface the transverse crosssection of which is constituted by a straight line extending throughoutthe breadth of the skis, the outer lower surface of the lower boards ofthe two skis assuming thus structures that are exactly symmetrical withreference to a longitudinal vertical plane separating the two skis whenlying next to each other.

4. A pair of skis comprising two skis including each respectively one ofthe two boards obtained through the ripping of a shaped lath to form thelower members of the skis, each board having its ripped surface directeddownwardly, and an upper boardhaving a shape similar to that of thecorresponding lower board and contacting with said corresponding lowerboard along a surface the transverse cross section of which isconstituted by a straight line extending throughout the breadth of theskis, the grains of the superposed boards of each ski being orthogonalwith reference to one another.

5. A method for producing a pair of skis consisting in shaping a lath tothe outlineof a ski, ripping it along a surface parallel to its outersurface, shaping two further strips to form the upper boards of theskis, gluing atiroom temperature each ripped lath to the correspondingupper strip, the transverse cross section of the contact surface betweenthe ripped lath and the cooperating upper strip being constituted by astraight line extending throughout the breadth of the skis, the rippedsurfaces of the lath lying on the outside of the compound skis obtainedto produce ground-engaging surfaces that are exactly symmetrical for thetwo skis lying in side by side relationship with reference to alongitudinal vertical plane passing between them, bending each skiformed by the superposed upper strip Yand ripped lath and holding theskis in their bent positions during the drying of the glue between theripped lath and upper strip forming each of the skis.

6. A method for producing a pair of skis consisting in shaping a lath tothe outline of a ski, ripping it along a surface parallel to its outersurfaces, ripping a further shaped lath, gluing each ripped element ofthe lfirst lath to a ripped lelement of the second lath to form a skithe lower surface of Vwhich is constituted by the ripped surface of thefirst lath to obtain operative sliding surfaces that are exactlysymmetrical for both K 2,560,663 5 6 skis with reference to alongitudinal vertical plane REFERENCES CITED Segaratilg them when lyingin Side'by'sd? re' The following references are of record in thelatlonship, the grain of the superposed ripped me of this patent:

lath and upper strip in each ski lying orthogonal with reference to eachother, the transverse 5 UNITED STATES PATENTS cross-section of thecontacting surfaces vbetween Number Name Date the superposed rippedelements forming each ski 2,213,903 Davidson Sept. 3, 1940 extendingrectilinearly across the ski, bending 2,369,004 Andreef Feb. 6, 1945each ski formed by the superposed lath elements into final ski shape andholding them in their 10 FOREIGN PATENTS bent shape during the drying ofthe gluebetween Number Country Date the ripped elements. 68,226 SwedenApr. 20, 1929 ABEL ROSSIGNOL. 95,739 Sweden Mar. 16, 1939 199,506Switzerland Nov. 1, 1938 15 203,711 Switzerland June 16, 1939

